Project Summary Waterpipe tobacco (WT) smoking in the U.S. is common among young adults, with approximately 5.5 million current users. WT smoking is associated with many of the same health risks as cigarette smoking, but consumers often erroneously believe WT smoking is less harmful and less addictive than cigarette smoking. Marketing, including package design and digital marketing (websites and social media), is an effective tool used by the tobacco industry to communicate product health information to consumers. The Food and Drug Administration (FDA) has begun to prohibit certain claims on WT packaging and in marketing. Under Section 911 of the Family Smoking Prevention and Tobacco Control Act, manufacturers and retailers are prohibited from making unauthorized modified risk tobacco product (MRTP) claims, including statements that the product or its smoke: (1) results in reduced harm; (2) contains a reduced level of or presents a reduced exposure to a substance; (3) does not contain or is free of a substance; and (4) statements that use modified risk descriptors such as light, mild, low, or similar descriptors. In addition, manufacturers and retailers are also prohibited from making false and misleading claims on packaging and in marketing under Section 903. Some prohibited claims are easily identifiable, but others are more difficult to identify due to lack of specificity in the law and the implicit nature of some claims. Evidence is needed, specific to WT packaging and marketing, to identify claims and determine their influence on consumer harm misperceptions to inform future regulatory actions. The proposed study will address this gap by documenting claims on WT packaging and in digital marketing (websites and social media) and how such claims influence consumer perceptions and willingness to try WT. In Aim 1, we will identify WT product packaging and digital marketing through a comprehensive website review to identify manufacturers (who make WT) and retailers (who sell WT for onsite use, such as cafs and lounges). We will create a sampling frame of WT brands and flavors and will randomly select five flavors from 30 brand to purchase packaging. For digital marketing, we will use the same 30 brands of WT manufacturers and a random sample of 30 retailers with websites and social media accounts. We will capture all website content and 20 of the most recent posts from Facebook and Instagram, the two most popular social media platforms among young adults. In Aim 2, we will content analyze all of the packaging and digital marketing captured in Aim 1. We will then use an expert panel to determine whether claims found on packaging and in digital marketing are examples of prohibited claims. In Aim 3, we will conduct a randomized, online experiment with a nationally-representative sample of young adults to evaluate the impact of prohibited claims present on WT packaging and in digital media on young adults' willingness to try the product, perceptions of harm, and product appeal. The findings will help the FDA determine which claims consumers interpret in ways that the law prohibits; which could prompt the FDA to engage in additional rulemaking so consumers are not misled.